This guy has mad FOSS cred. I bet even his socks are made of free range organic open source wool released under a Creative Commons attribution share-alike licence.
Seriously though, that sounds like an amazing setup. I always wanted to mess with gadget bridge some more. I have a number of old MiBand devices lying around as well as a Bip. The third party apps for that thing had more features than almost every fitness tracker I've had potentially even including my Garmin watch. What tools do you use to analyze/review/visualize the gadget bridge data?